Treatment of paper or textile fabrics



Patented Aug. 27, 1946 UNITED, STATES PATENT OFFICEI' TREATMElQT OF PAPER on TEXTILE FABRICS William Charlton, Stanley Graham Jarrett, and Eric Everard Walker, Blackley; Manchester, England, assignors to Imperial Chemical Industries Limited, a corporation of Great Britain No Drawing.

This invention relates to a treatment of paper form of a solution or aqueous dispersion and then causing the monomeric compound to polymerise thereon, the polymerisation being effected in' the presence of a polymerisation catalyst and under conditions in'which the action of molecular oxygen (e. g., atmospheric oxygen) is diminished or entirely suppressed.

The paper may be of any kind within the common meaning of the term. I The textile fabrics may be woven or knitted and composed of fibres which may be animal or vegetable, for example, wool or cotton or jute; or of vegetable origin, for example viscose or acetate rayon; or entirely synthetic, for example synthetic linear polyamide (nylon) fibres; or mixtures of such fibres.

The monomeric readily polymerisable compounds are those containing the group CH2==C1 and they, include, for example, acrylic acid, methacrylic acid, esters of acrylic acid, esters of methacrylic acid, acrylonitrile, methacrylamide, vinyl esters,- vinyl ethers and styrene; Of these, the lower alkyl or alkylene esters of acrylic acid and of methacrylic acid, for example, methyl and ethyl acrylates and methacrylates, are especially suitable; the higher alkyl esters (wherein the alkyl group has more than 6 carbon atoms), for example, 2-ethylhexyl methacrylate and octadecyl methacrylate, are less suitable since they polymerise more slowly or to a lesser extent under the conditions employed. B-ethoxyethyl methacrylate and n-butyl methacrylate are also suitable, the former being the more easily polymerand/or other ingredients customarily incorporated in fluids used for finishing paper or textile fabrics. v

Particularly suitable polymerisation catalysts are persulphuric acid or water-soluble persulphates, for example, ammonium persulphate, but other polymerisation catalysts may be used. The persulphuric acid or persulphates or other polymerisation catalysts are conveniently used in the form of their dilute aqueous solutions, and they Application March 8, 1944, Serial In Great Britain February 15,

9 Claims. (c1.117-'-139.5)-;

' may be applied to the paper or fabrics by soaking or impregnating.

As said, the polymerisation is carriediout under conditions in which the action of molecular oxy= gen is diminished or entirely suppressed. These conditions are achieved by carrying out the polymerisation in the absence of air or oxygen and/or by using oxygen-acceptors. Particularly suitable oxygen-acceptors include sulphurous acid or its water-soluble salts, as well as water-soluble hydrosulphites and pyrosulphites, for example, the sodium or calcium salts. When using such oxygen acceptors, and it is preferred to use them,

they are conveniently used in the form of their aq eous solutions. By using oxygen-acceptors pol erisation can be efiected rapidly at temperatures as low as 30 C. or even lower.

In a convenient method of operating .the proc-, ess of the invention, an aqueous medium having applied to the paper or textile fabric, and the persulphate and an oxygen-acceptor are applied, simultaneously or before or after, dissolved in an aqueous medium or media. Successive applications of the media may be made if desired,

that is to say, the process of the invention may be repeated once or more' than once.

The choice between the use of solutions or of emulsions containing readily polymerisable mon- 80 omeric compounds is governed largely by the choice of'said' compounds and, to some extent, by the nature of the paper or fabric being used. The use of aqueous emulsions is usually more economic and convenient, but the use of solutions is, in general, of wider applicability. When solutions are used, all or part of the solvent should be water or some other ionising liquid, for example, dimethylformamide; a useful solvent is ethyl alcohol containing about 10% or more by weight 40 of water.

The monomers may be caused to polymerise by known means, subject to the hereinbefore mentioned requirements. The efiects produced vary with the nature of the monomer and the amount using more than one monomer. The deposition of small amounts of polymers on the paper or fabrics causes small changes in handle, whilst the deposition of larger amounts of polymers gives fabrics resembling oiled-silk, or fabrics which can be used as interlayers in the fabrication of laminated structures. The amounts of polymer deposited depend on the conditions of working, and

maybe varied as desired in accordance with experience gained by trial.

themonomer dispersed or emulsified therein is of polymer deposited, and may be modified by The invention is illustrated but not limited by the following examples, in 'which the parts are expressed by weight:

Example 1 An emulsion of fi-ethoxyethyl methacrylate' is made by stirring 80 parts of th monomer into 70 parts or an aqueous solution containing 3.5 parts of wheat starch and 0.7 part of technical oleyl sodium sulphate. v

A cotton fabric is impregnated with the above emulsion, the excess of which is removed by squeezing or rolling, and the so treated fabric is then immersed in a bath, maintained at 40 C. made by dissolving 1 part of ammonium persulphate, 0.5 part of sodium hydrosulphite and 20 parts of common salt in 78.5 parts of water. After 15-30 minutes, the fabric is withdrawn from the bath, rinsed several times in hot water, and dried. "The amount of polymer formed on the cloth is 20-30%, but this may be increased to, e. g., 50% by a second treatment.

The fabric having 20-30% of polymer deposited thereon is stifiened, and the fabric having 50% of polymer deposited thereon is stiffened we still greater extent. The finish is wash-fast.

Example 2 i A mixture of 18 parts of methyl methacrylate and 12 parts of dibutylphthalate is emulsified with water in the manner described in Example 1, to give 100 parts of emulsion.

This emulsion is applied to cotton fabric and polymerisation efiected in the manner described in Example 2. the amount of polymer formed on the cloth under these conditions being 10-12%.

The so treated fabric is similar in appearance to the original, fabric, but has a harsher handle, and is stiffened slightly.

Example 3 A solution of methyl methacrylate is made by stirring 3 parts of the monomer into a mixture of 7.5 parts of water and 22.5 parts of ethyl alcohol.

Washed woollen cloth is immersed in this solution. After standing for 30 minutes, 0.33 part ofammonium persulphate and 0.165 part of sodium hydrosulphite are stirred in, and the cloth and the solution are heated at a temperature of 30 C. for 30 minutes. The cloth is removed from the solution, kept at 30 C. for ,2 hours, rinsed thoroughly in Water and then dried. Methyl methacrylate polymer is formed on the cloth to the extent of 40% of its weight.

Example 4 -A solution of 5 parts of methacrylic acid and 2 parts of ammonium persulphate in 93 parts of water is used-to impregnate a washed woollen serge cloth. After standing for 30 minutes, the cloth is removed from the solution, squeezed, exposed tov anatmosphere of carbon dioxide for 30 minutes, washed and dried. The gain due to polymerisation of methacrylic acid is about 31% of the weight of the cloth.

' 2 Example 5 Woollen cloth is washed in water, dried and then soaked for 30 minutes'in a solution of parts of methacrylamide and 2 parts of ammonium persulphate in 88 parts of water. The

cloth is squeezed to remove excess of the solution and exposed to a current of sulphur dioxide or carbon dioxide. In either case, the fabric gains in weight by about 8% due to deposition of,

methacrylamide polymer.

Example 6 Absorbent paper, is soaked in warm water, removed, dried and then immersed for 10 minutes in an emulsion made by stirring 30 parts of styrene with a solution of 5 parts of technical' sodium oleyl sulphate in 65 parts of water. The

paper is then transferred to a solution of 1 part of ammonium persulphate, 0.5 part of sodium hydrosul'phite and 20 parts of common salt in 78.5 parts of water. time, the paper is removed, washed with warm water and dried. The paper gains in weight by about 14% due to deposition of the polymer.

When the aboverecipe is repeated, using the a same weight of a, mixture of methyl methacrylate and dibutyl phthalate (3:2 by weight) in place of the styrene,- the paper. gains in weight by about 18%.

Example 7 An emulsion of vinyl acetate in water is made by stirring -parts of vinyl acetate with a solution of 5 parts of technical sodium oleyl sulphate in 65 parts of water. Cotton fabric is soaked in this emulsion for 60 minutes and then transferred to a solution of 2 parts of ammonium persulphate and 1 part of sodium hydrosulphite in 97 parts of water. After standing for minutes, the fabric is removed, rinsed in warm water and dried. The

amount of polymer deposited amounts to 26% of the fabric weight. The amount of polymer deposited is increased to 43.5% by repeating the immersions for the same times.

Example 8 Cotton cloth is padded with a solution of 18 parts of calcium acetate in 82 parts of water, excess of the solutionis squeezed out, and the wet fabric is soaked for a few minutes in a solution of 25 parts of sodium sulphite in parts 'of water. The cloth is removed, rinsed in cold water and dried; the cloth now carries about 10% of its weight of calcium sulphite. The so treated cloth is then immersed in a solution of 2 parts of ammonium persulphate and 10 parts of methyl acrylate in 88 parts of water, the solution is heated to a temperature of 30 C. and the cloth is kept in this solution at this temperature for 25 minutes. dried. Methyl acrylate'p'olymer is formed .on the cloth'to the extent of 36% of its weight.

We claim:

1. A process for treating a fibrous material which comprises applying to said material a monomeric, readily polymerizable compound containing the group CH2=C: distributed in a liquid medium comprising an ionizing liquid, and efiecting polymerization in the presence of a. polythe polymerization catalyst comprises ammonium persulf'ate. 5

4. The process of claim 1 characterized in that After standing for a short The fabric is removed, rinsed and 2,406,454 5 A the polymerization catalyst is incorporated in the 8. The process of claim 1 characterized in that fibrous material from aqueous solution. the monomeric compound is in the form of an 5. The process of claim 1 characterized in that aqueous solution. the sulfur compoundoi' the class named is used 9. The process of claim 1 characterized in that in the form of its aqueous solution. the monomeric compound is in th form of an 6. The process of claim 1 characterized in that aqueous emulsion. the monomeric compound is applied in successive treatments. WILLIAM CHARLTON.

7. The process 01 618,11 1 characterized in that STANLEY GRAHAM JARRE'IT. the monomeric compound is dissolved in said 10 ERIC EVERARD WALKER;

liquid medium. 

